

Alam, A. 2014. Soil degradation: a challenge to sustainable agriculture. International Journal of Scientific Research in Agricultural Sciences 1(4):50-55.
Ammurabi, D.S., Anas, I. and B, Nugroho. 2020. Partly substitution of chemical fertilizer with bio-organic fertilizer on maize (Zea mays). Jurnal Ilmu Tanah dan Lingkungan 22(1):10-15, doi:10.29244/JITL.22.1.10.15 (in Indonesian).
Damar, H., Ziadi, N., Lafond, J. and Parent, L.E. 2021. Long-term impact of fertilizer sources on cyclic P budget and soil P status under ley farming system. Nutrient Cycling in Agroecosystems 119(2):165-180, doi:10.1007/S10705-020-10112-7.
Dimkpa, C.O., Fugice, J., Singh, U. and Lewis, T.D. 2020. Development of fertilizers for enhanced nitrogen use efficiency-Trends and perspectives. Science of The Total Environment 731:1-5.
Dragović, N. and Vulević, T. 2020. Soil Degradation Processes, Causes, and Assessment Approaches. Springer Nature Switzerland AG 2020 W. Leal Filho et al. (eds.), Life on Land, Encyclopedia of the UN Sustainable Development Goals, doi:10.1007/978-3-319-71065-5_86-1.
Feng, J., Hussain, H.A., Hussain, S., Shi, C., Cholidah, L., Men, S., Ke, J. and Wang, L. 2019. Optimum water and fertilizer management for better growth and resource use efficiency of rapeseed in rainy and drought seasons. Sustainability 12(703):1-18.
Ichami, S.M., Shepherd, K.D., Sila, A.M., Stoorvogel, J.J. and Hoffland, E. 2019. Fertilizer response and nitrogen use efficiency in African smallholder maize farms. Nutrient Cycling in Agroecosystems 113:1-19.
Irawan, Setyorini, D. and Rochayati, S. 2020. Projection of Fertilizer Needs in the Agricultural Sector Through a Dynamic System Approach. Agricultural Research and Development Agency, Ministry of Agriculture, Bogor, Indonesia (in Indonesian).
Jalpa, L., Mylavarapu, R.S., Hochmuth, G.J., Wright, A.L. and van Santen, E.. 2020. Apparent recovery and efficiency of nitrogen fertilization in tomatoes grown on sandy soils. HortTechnology 30(2):1-8, doi:10.21273/horttech04480-19.
Kotschi, J. 2015. A Soiled Reputation Adverse impacts of mineral fertilizers in tropical agriculture. Heinrich Böll Stiftung (Heinrich Böll Foundation), WWF Germany.
Logan, T.J. 1990. Chemical degradation of soil. Advances in Soil Science 11:187-221.
Mensah, A.K. and Frimpong, K.A. 2018. Biochar and/or compost applications improve soil properties, growth, and yield of maize grown in acidic rainforest and coastal savannah soils in Ghana. International Journal of Agronomy, Volume 2018, Article ID 6837404, doi:10.1155/2018/6837404.
Mulyani, A. and Agus, F. 2017. The need and availability of reserved arable land realize Indonesian as the world food supplier in 2045. Analisis Kebijakan Pertanian 15(1):1-17, doi:10.21082/akp.v15n1.2017.1-17 (in Indonesian).
Patrick, M., Tenywa, J.S., Ebanyat, P., Tenywa, M.M., Mubiru, D.N., Basamba, T.A. and Leip, A. 2013. Soil organic carbon thresholds and nitrogen management in tropical agroecosystems: concepts and prospects. Journal of Sustainable Development 6(12):31-43.
Soil Research Institute. 2009. Technical Guidelines for Chemical Analysis of Soil, Plants, Water and Fertilizers. Center for Research and Development of Agricultural Land Resources, Indonesia (in Indonesian).
Voltr, V., Menšík, L., Hlisnikovský, L., Hruška, M., Pokorný, E. and Pospíšilová, L. 2021. The soil organic matter in connection with soil properties and soil inputs. Agronomy 11:779, doi:10.3390/agronomy11040779.
Wibowo, H. and Kasno, A. 2021. Soil organic carbon and total nitrogen dynamics in paddy soils on the Java Island, Indonesia. IOP Conference Series: Earth and Environmental Science 648:012192.
Widowati, LR., Nursyamsi, D., Rochayati, S. and Sarwani, M. 2011. Nitrogen management on agricultural land in Indonesia. Proceedings of International Seminar on Increased Agricultural Nitrogen Circulation in Asia: Technological Challenge to Mitigate Agricultural N Emissions. Taipei, Taiwan, September 27-28, 2011.
Winarso, S., Hermiyanto, B., Romadhona, S., Pandutama, M.H., Setiawati, T.C. and Indasah. 2020. Effectiveness of the combination of biopellet, biochar, chicken manure and fish waste to the improvement of chemical properties of sandy soil and soybean plant growth. Journal of Degraded and Mining Lands Management 7(4):2363-2371, doi:10.15243/jdmlm.2020.074.2363.
Winarso, S., Subchan, W., Haryanti, A., Setiawati, T.C. and Romadhona, S. 2021. Increasing the abundance of microorganisms in a regosol soil using biopelet fertilizer composed from biochar, chicken manure, and shrimp waste to increase soil fertility. Journal of Degraded and Mining Lands Management 8(4):2881-2890, doi:10.15243/jdmlm.2021.084.2881.